The aim of this study was to investigate the effects of boric acid in experimental acute sciatic nerve injury. Twenty-eight adult male rats were randomly divided into four equal groups (n = 7): control (C), boric acid (BA), sciatic nerve injury (I) , and sciatic nerve injury + boric acid treatment (BAI). Sciatic nerve injury was generated using a Yasargil aneurysm clip in the groups I and BAI. Boric acid was given four times at 100 mg/kg to rats in the groups BA and BAI after injury (by gavage at 0, 24, 48 and 72 hours) but no injury was made in the group BA. In vivo electrophysiological tests were performed at the end of the day 4 and sciatic nerve tissue samples were taken for histopathological examination. The amplitude of compound action potential, the nerve conduction velocity and the number of axons were significantly lower and the myelin structure was found to be broken in group I compared with those in groups C and BA. However, the amplitude of the compound action potential, the nerve conduction velocity and the number of axons were significantly greater in group BAI than in group I. Moreover, myelin injury was significantly milder and the intensity of nuclear factor kappa B immunostaining was significantly weaker in group BAI than in group I. The results of this study show that administration of boric acid at 100 mg/kg after sciatic nerve injury in rats markedly reduces myelin and axonal injury and improves the electrophysiological function of injured sciatic nerve possibly through alleviating oxidative stress reactions.

AIM: To investigate the effects of systemic application of bone marrow-derived mesenchymal stem cells in a compression model of peripheral nerve injury. MATERIAL and METHODS: Twenty-four male Wistar albino rats were randomly divided into 3 equal groups (n=8): Control (C), injury (I), and stem cell and injury (SI). The sciatic nerve of the rats in the I and SI groups was subjected to clip compression for 5 minutes. Moreover, approximately 5x10(5) bone marrow-derived mesenchymal stem cells were given via tail vein of the rats in the SI group immediately after clip compression. The nerve conduction velocities and amplitudes of the rats were measured 30 days later. Then, the sciatic nerves were removed, and myelin damage grading and axon counting were performed. The data were analyzed by OneWay ANOVA and Tukey's post-hoc test. P values less than 0.05 were considered to be statistically significant. RESULTS: While the proximal, distal and mean latency values were higher in the I and SI groups than in the control group, the same measurements were lower in the SI group than in the I group. While the nerve conduction velocity, the amplitude of compound muscle action potential and the number of axons were lower in the I and SI groups than in the control group, the same measurements were higher in the SI group than in the I group. Moreover, myelin damage was found to be lower in the SI group than in the I group. CONCLUSION: Systemic application of bone marrow-derived mesenchymal stem cells in a compression model of peripheral nerve injury has a positive impact on both myelin sheath and axon survival.

AIM: To investigate the effects of systemic application of Theranekron on peripheral nerve healing after compression type peripheral nerve injury. MATERIAL and METHODS: Twenty-one female Wistar albino rats were randomly divided into 3 groups (n=7): Control (C), injury (I), and Theranekron (T). The right sciatic nerves of rats in the I and T groups were compressed via an aneurysm clip for 5 minutes and 0.3 ml Theranekron D6 was applied via subcutaneous administration once a week in the T group for a total period of four weeks. Nerve conduction velocity and proximal and distal latency of the rats were measured at the end of day 30. The right sciatic nerves of the rats were then removed and myelin damage grading, axon counting, fibrosis assessment, caspase-3, and NF-kB immunochemical staining were performed. The data were analysed statistically and a p value of less than 0.05 was considered to be significant. RESULTS: Axonal degeneration, vacuolization and myelin destruction were found to be markedly greater in group T. Fibrosis and caspase-3 immunoreactivity were less intense in group T. There was a statistically significant difference in the electrophysiological results of groups I and T. However, there were no statistically significant differences in axon number and NF-kB immunochemical evaluation of groups I and T. CONCLUSION: The findings of this study show that Theranekron decreases axonal and myelin damage after sciatic nerve injury and that this neuroprotective effect of Theranekron can be attributed to its anti-inflammatory effect on pro-inflammatory cytokine levels.

Yy Aim: To investigate the effects of local and systemic administration of methyl palmitate on the formation of epidural fibrosis. Material and Methods: Twenty-eight rats were randomly divided into four equal groups (control, Spongostan, local methyl palmitate and orally methyl palmitate) and laminectomy was performed between T11 and L1 in all rats. Local methyl palmitate (300 mg/kg) was applied with Spongostan; methyl palmitate (300 mg/kg) was given orally three times per week on different days for a total period of 4 weeks. Four weeks later, the vertebral column from T9 to L3, including the paraspinal muscles and epidural scar tissue, was removed en bloc and epidural fibrosis and arachnoidal involvement was graded and evaluated histopathologically. Kruskal-Wallis and Pearson Chi-Square test were used for statistical analysis. A statistically significant p-value was determined as p < 0.05. Results: The grading of epidural fibrosis was lower at a statistically significant level in orally-administrated methyl palmitate groups compared to the control and spongostan groups (p < 0.05). Conclusion: The findings of this study show that oral methyl palmitate decreases the formation of epidural fibrosis and that this effect of methyl palmitate could be mediated by reducing the functions of inflammatory cells such as macrophages, neutrophils and fibroblasts, including anti-inflammatory and antioxidant effects.

AIM: To investigate the effects of local and systemic administration of etanercept on the formation of epidural fibrosis. MATERIAL and METHODS: Twenty-eight rats were randomly divided into four equal groups (Control, Spongostan (TM), Local etanercept and Systemic etanercept) and laminectomy was performed between T11 and L1 in all rats. Spongostan (TM) was soaked with saline (0.1 mg/kg), local etanercept (300 mu g/kg) was applied with Spongostan (TM) and systemic etanercept (300 mu g/kg/week) was applied subcutaneously. Four weeks later, the vertebral column from T9 to L3, including the paraspinal muscles and epidural scar tissue, was removed en bloc, and epidural fibrosis and arachnoidal involvement were graded and evaluated histopathologically. RESULTS: The grading of epidural fibrosis was statistically significantly lower in systemic and local administration of etanercept groups compared to the control group (p < 0.005), but systemic etanercept administration was more effective. CONCLUSION: Systemic administration of etanercept can be effective in reducing epidural fibrosis in rats after laminectomy.

Many complications related to the resection of an ossified posterior longitudinal ligament via the anterior approach have been reported. Postoperative neurological deterioration is one such complication that may appear due to massive anterior spinal cord herniation related to a dural defect following resection of the ossified posterior longitudinal ligament. Specifically, spinal cord herniations have been reported to be associated with posterior approaches, and a large number of theories regarding this association have been offered by various authors. However, anterior spinal cord herniation is extremely rare, and its pathophysiology has not yet been explained. In this case report, we report a male patient who experienced anterior spinal cord herniation following anterior surgery. Spinal cord herniation may develop following the removal of the anterior cervical corpectomy. Therefore, surgeons should be aware of this condition when planning treatments for cervical spondylotic myelopathy via the anterior approach.